AFAIK, you should have no problem converting MP4 to MKV using Handbrake, but it would help to have more information, which edition and version of Linux Mint, like which Handbrake "preset" did you use, and what Handbrake version are you using? How about a screenshot of Handbrake?

And as was just suggested, if you just want to convert MP4 to MKV, there are simple applications like WinFF, Curlew, Transmagedon, FF Multi Converter, Avidemux, etc...

This doesn't really answer your question, but you can use ffmpeg to switch to the mkv container without having to reencoding both the audio and video, thus not losing any quality.

I basically agree with this ... but if you're triyng to compress the video you could just set the encoder to simply copy the video stream. AFAIK Handbrake has this option. You don't save much space by compressing the audio.

Flemur wrote:
- Have you tried just changing the file's extension? (I've changed it the opposite way [m4v->mp4] with handbrake's output files).

Changing the filename of an m4v to mp4 is not a problem, because with either way it's still the mp4 container. But simply changing the mp4 to mkv in a file name does not change the container, the contents will still be in a mp4 container. If the OP isn't doing any type of editing, the best thing he can do is copy the video/audio into the mvk container, either with ffmpeg or with Handbrake if Handbrake allows both video/audio to be copied without reencoding (or any app that has the pass through feature).

BTW, there is a setting in Handbrake to make the files have the mp4 extension. It is in File >> Preferences, general tab. Untick the box "Use iPod/iTunes friendly (.m4v) file extension for MP4."

If you're going to be doing any conversion ... you didn't say but I think you're probably wanting to shrink the file ... you need Mediainfo. The package name is mediainfo-gui, install it via software manager or synaptic. Open the file with mediainfo, switch to text mode, and copy/paste the text here.

It may be a codec problem wiith Handbrake. Does the original file play on the same machine with audio?

I am struggling here. I am trying to convert an MP4 File to MKV and each time I do it with Handbrake, I lose the audio. Any pointers? Would very much appreciate it. Thank you.

Hi there ! i am using Handbrake just recent days and i had the similar "loss of Audio" when "Start Encoding" was finished , yesterday and earlier today it functioned well to Encode from a DVD to MKV with audio also - the only change i saw was : the tab "Audio List" was empty , i tried to click Reload Defaults without any reaction ( that functioned earlier ) . so i manually added codecs in "Audio List" with happy result . / \